1. Field of the Invention
The present invention relates to improved synthetic filaments having a trilobal or tetralobal cross-sectional shape with convex curves along the contour of each lobe. At least one continuous void is located in each lobe of the filament. The filaments are especially suitable for making carpets which exhibit low glitter and have high bulk and excellent soil hiding performance.
2. Description of the Related Art
In Tung, U.S. Pat. Nos. 5,108,838, 5,176,926, and 5,208,106 synthetic filaments having various trilobal and tetralobal cross-sectional shapes are disclosed. These filaments are free of flat surfaces and have convex curves, connected by cusps, along the contour of each lobe. The filaments may be used to make carpet yams which, in turn, may be tufted into backing materials to produce carpets having low glitter and high bulk.
However, one disadvantage with such filaments and carpets is that they may exhibit poor "soiling performance". By the term "soiling performance", it is meant the apparent resistance of a fiber to visible soiling which may be independent of the soiling which actually occurs. Now, in accordance with the present invention, it has been found that the soiling performance of the above-described filaments may be improved by incorporating voids therein which extend continuously along the lengths of the filaments.